A resistance variable material has a characteristic in which its resistance value significantly changes according to a magnitude or polarity of an electric pulse applied and the changed resistance value is maintained. In recent years, a resistance variable element using the resistance variable material and a semiconductor apparatus such as a nonvolatile memory apparatus using the resistance variable element have been developed by utilizing such characteristics.
Patent document 1 discloses a configuration of an example of a conventional nonvolatile memory apparatus using the resistance variable element. FIG. 11 is a schematic block diagram showing a configuration of the conventional nonvolatile memory apparatus. As shown in FIG. 11, a nonvolatile memory apparatus 80 comprises a memory circuit 82 and a memory region 70 connected to the memory circuit 82. The memory region 70 includes bit lines B1 to B4 (lower electrodes 74) arranged to extend in parallel with each other, word lines W1 to W4 arranged to cross the bit lines B1 to B4 (upper electrodes 78), resistance variable elements 52 which are arranged at crossing regions between the bit lines and the word lines, and protective resistors 54 connected in parallel with the resistance variable elements 52. Each bit 50 includes the lower electrode 74, the upper electrode 78, the resistance variable element 52 and the protective resistor 54. The memory circuit 82 includes bit pass transistors 84 respectively connected to the bit lines B1 to B4. The bit pass transistors 84 respectively have bit pass gates 64 and are respectively connected to load transistors 86 respectively having load gates 66 and to inverters 90.
In FIG. 11, active layers are illustrated as an array of resistors connected between the lower electrodes 74 (bit lines B1 to B4) and the upper electrodes 78 (word lines W1 to W4).
In the nonvolatile memory apparatus configured as described above, an ON-voltage is applied to the gate of the bit pass transistor 84 and a second ON-voltage is applied to the gate of the load transistor 86, thus applying a voltage pulse to a desired word line. Thereby, data is stored in the resistance variable element 54 connected to the word line.    Patent document 1: Japanese Laid-Open Patent Application Publication No. 2003-68984